body {
  display: flex;
  margin: 0;
  font-family: Arial, sans-serif;
  height: 100vh;
}

#sidebar {
  width: 220px;
  background-color: #f0f4f8;
  padding: 20px;
  border-right: 1px solid #ccc;
  box-shadow: 2px 0 5px rgba(0,0,0,0.05);
}

#content {
  flex-grow: 1;
  padding: 30px;
  overflow-y: auto;
  background-color: #ffffff;
}

button {
  width: 100%;
  margin-bottom: 12px;
  padding: 12px;
  font-size: 16px;
  border: none;
  background-color: #2196f3;
  color: white;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.3s ease;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

button:hover {
  background-color: #1976d2;
}

.question {
  margin-bottom: 15px;
  background: #f9f9f9;
  padding: 12px;
  border-left: 4px solid #2196f3;
  border-radius: 4px;
}

audio {
  display: block;
  margin-bottom: 15px;
}

/* 模态框样式 */
.modal {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.5);
  z-index: 1000;
  overflow-y: auto;
  padding-right: 10px;
}

.modal-content {
  background-color: white;
  margin: 10% auto;
  padding: 20px;
  width: 50%;
  border-radius: 5px;
  position: relative;
}

.close {
  position: absolute;
  right: 15px;
  top: 10px;
  font-size: 24px;
  font-weight: bold;
  cursor: pointer;
}
